Can confirm. Source: I used to work for NASA, and I'm a private pilot. There are literally millions of electrical connections that get made on aircraft and spacecraft on a regular basis and I can't think of ever hearing of an incident caused by one of them being made backwards. (Now, mechanical connections getting made backwards is not unusual. That's why you check to make sure that the flight control surfaces move in the right direction as one of the last checklist items before you take off. Every. Single. Time.)
I can think of very few kinds of connectors for which this type of error is even possible. You would need two cable terminations which can connect to each other, for which either side can plug into the same jack.
So either the ends are literally the same (e.g. Anderson Powerpole), or there is some kind of weird symmetry or inadequate keying. Or maybe the two cables don’t connect directly and instead go through some of kind of interface? The latter is fairly common in networking, e.g. “feed-through” patch panels and keystone jacks and quite a few kinds of fiber optic connectors.
All of these seem like utterly terrible ideas in an application where you would take the thing apart after final assembly and where the person doing the disassembly or reassembly could possibly access the wrong side of the panel.
One guy in our workshop had to provide DC to a display with a round 4-pin connector. He soldered two neighboring pins to Gnd and the other two to Vcc. There were two chances to short the powersupply, one to brick the display and one to get it right. Guess what we had to replace until we found out.
A break out box could very sensibly have both sides of the connector on it and then have the various pins broken out into individual connections for flexibility.
In that case keying or whatever isn't going to prevent you from connecting to the wrong side, because both sides are present.
Looks like the author tried to double-power the motor with both the spacecraft motor driver and through the breakout box that MITMs the driver and the motor. In such event, the free-wheeling diode in the driver will allow reverse current to be fed back to the driver's power supply up to certain amounts. This will absorb back-EMF, or energy from "regen" from the motor.
I'm suspecting the breakout wasn't literally sitting between the driver and the motor, but rather all internal connections are broken out to the box for testing; and likely the author's mistake was to not mess with the spacecraft to temporarily disconnect the driver.
But I'm not sure if I'd "just" made the right call and done so nonchalantly on a Mars rover to launch in few weeks.
There have been several cases of the landing gear up/down lever getting wired backwards during maintenance. Not to worry, the gear has a 'squat switch' sensor that prevents the gear from being raised when the plane is on the ground. Unless you taxi over a bump and the switch decides it's now airborne. Crunch.
It depends on what you mean by "that". Getting control surfaces actually reversed is not very common, but it does happen, typically after maintenance when a mechanic inadvertently re-connects a control cable backwards.
Control cables also can and do break, but that too is fairly rare.
What is not rare is control mechanisms jamming. Here is an example:
